Speedometer drive



April .1 1924. y

H. J. MURRAY SPEEDOMETER DRIVE Filed Apri; 17? 1922 2 sheets-sheet 1INVENTOR wml/da,

ATTORNEY w Y A m RD wm T ,MM .O .JD m HP S April 1924.

Filed April 17. 1922 2 sheets-sheet 2 /ffl fla/l. Arif/ffl!!! INVENTORHama/d JMJ/fray ATTORNEY Patented Apr. 1, 192.4.

UNITEDA vSTATES Howm'a. MURRAY, or NEW Yonx, n'. Y.

SPEEDOMETEB Dmvn .To all 'whom t` may concern:

Be it known :that I, HOWARD J. MURRAY,

a citizen of the United States, and resident of New York 'c ity, in thecounty of Klngs and State of New York, have invented certain new anduseful Improvements in Speedometer Drives, of which the following is aspecification.

The invention relates in general to a Hexible power transmitting.shafting of the type in which vthe power is transmitted by reciprocatorymotion and the invention specifically relates to a drive for actuatingan instrument, such as a speedometer, from a rotating power shaft, suchas a transmission shaft, a function of which is to be indicated by theinstrument.

In speedometer drives now in general use in automotive vehicle equipment1t is an approved practice to mount the speedometer on the springsupported vehicle body and to make connection with one of thetransmislsion shafts usually with the part Vof the driven shaft whichextends out of the trans-V mission housing. This type vof drivenecessitates the use of some form of flexible driving connection so thatthe speedometer is free tov move bodily relative to the transmissionshaft. The forms of speedometers now in general use include a mainrotating drive shaft andl the flexible connection between .thespeedometer shaft and the transmission shaft includes a rotating shaftelement having geared connections at one end with the transmissionlshaft and using a direct driving connection at the opposite end withthe speedometer shaft. v This rotating form of drive has numerousobjections when considered in its practical operation. For instance, thepublic has not been educated tolubricate the speedometer norits drive.As the result of this lack of lubrication, and also due to the factthatwhen lubricated, the oil leaked `from the ro- 45- tatable flexibleshaft, it not infrequently happens that some part of the drivingconnectlon becomes stuck. This l sticking becomes particularlynoticeable when the drive has been inactive for sometime and further theparts are apt to rust in place. Under these conditions as soon as thepower transmission shaft is caused to. rotate it tears some part of thedrive, strips the gears, twists the shafting and frequently causes anirregular actuation of the'instrument.

Further the rotating type of'iexible drive manifests a tendency to wearin thevicinity of sharp bends and unlessextreme care is taken in the mhining of the intermeshing gears, an irregularity in action andexcessive wear is apt to occur at the geared connections. Furtherchanges in temperature cause a contraction and expansion which thus varthe locationpof moving parts and this shi ting of arts 'becomes'obJectionable 'especially7 in t e case, of meshing gears.

PAT-ENT OFFICE.

The primary Vobject of .the'present invention is to provide a simple,easily manufactured, and therefore inexpensive form of instrument drivewhich when applied to use as a speedometer drive will avoid theobjections inherent in the use of the resent form of rotatingflexible'shafting an at the same time retain its advantages.l

Another object of the invention is to pro vide a self-lubricatingspeedometer drive which can function carry lubricant from thetransmission casing or other available .source of supply through thedrive to the speedometer without necessarily providing partsparticularly intended for this purpose.

Another object of the invention is to proL videv a single, comp-leteunitary article of manufacture which can be designed and soldforinstallation on transmission casings of the standard approved formand which is designe-d to drive not only the different forms ofspeedometers employing a rotating shaft but which will also'drive aAspeedometer of the type which is actuated by a reciprocatory member,one form of which speedometer is described in my co-p'endingapplication, entitled Electric speedometers, filed June 20, .1922,Serial No. 569,759, and another form of which is describedin mycopending application Serial No. 569,7 60 filedJune 20, 1922. Variousother objects and advantages of the invention will be in part obviousfrom an inspection of the accompanying drawin s and in part will be morefully set forth 1n the following particular description of one form ofmechanism embodying my invention, and the'nvention also consists incertain novel features of construction and combination of partshereinafter set forth and claimed. y y

In the following particular description, the invention will be disclosedin connection with a conventional form of speedometer of the rotatingshaft type so as to illustrate the adaptability of the disclosureto-drive anyof the usual forms ofginstruments which employ a rotatinshaft, but it is to be understood that the isclosure, with obviousmechanical changes, can be adopted todrive-other forms of instruments,andin Figure 4 there is dis-- closed the suggestion vof connecting thedrive to a reciprocating member rather than to the rotating shaft,common in the present forms `of speedometers. Further, the invention .isshown in -connection with a; supplemental' housing on the transmissioncasin of an automotive vehicle Apower plant to i lustrate theadaptability of the disclosure to present approved structures, but itis-to be underf stood that the drive ma'yrec'eive ower from any rotatingpower member an with obvious changes, from any reciprocating powermember. i

In the accompanying drawings: j

Figure 1 is a fragmentary sectional vieu7 of apart ofan automobiletransmission casing and part .of a rotating shaft driven speedometerwith a preferred'embodimentV of my invention constituting the drivetherebetween; 1 i

a'Figure2 is an enlarged vertical sectional view taken on the line 24-2of Figure 1; Figure 3 is `a similar v iewtakenon'the line 3- 3fof Figure1; and

Figure 4 is a detailed axial sectional view. of .a modified form. of,-connectionbetween the flexible drive disclosed in the other igures anda formofspeedometer' which 'em` ploys a reciprocatory actuating member.

larly to Figure 1 there is shown achange gear containing transmission'casing 10 from which projects the usual propeller shaft 11. Surroundingthe projecting end 12 of the shaft is a supplemental .housing 1 3 whichwith the housing 10 simply as a transmission housing. In' the presentdisclosure a cam will be referred to hereinafter collectively 14 iskeyedl to the projecting portion 12 of the shaft within the housing 13.The hous-, ing is lrovided with a laterally extending screw t Kreadedopening 15. ,'It is to be understood that the construction, as thus 'fardescribed, except that a gear is usedin place of the cam 14' and a shaftcarrying'bushing `is threaded into the opening 14, constitutes aconventional form of construction for accommodating one end Aof thespeedometer drive now in general use.

Instead of the usual sleeve a bushing 16 is threaded into the opening15, which bushing has abore extending axially therethrough. The innerportion of the bore is enlarged to form a spring housing' and plungerguideway 17. A round ended' cam lunger 18 is mounted in the guideway17 vor reciprocatory movement and is maintained in 'bearingengagement withthe face 19 of the cam l14' by means of a spring20` disposed in theguidewayj back of the `in thebus ling to prevent rotary movement oftheplunger. This pin and slot connection can be omitted in those .caseswhere the plungeris non-circular in cross-section orv where sli lit`rotary movement is -unobjecwhich extends through the bushing 16 and' ismaintained out ,of contact. with the walls y of the guideway 17by'meansof the spring 20.4 It willbe lunderstood from thiscon-` struction thatthe spring will store energy when compressed 'which energy is used tovpull the rod in; its return movement. `It is obviously withi'nthe lscopeof this disclosure to osition another spling, preferably a wearerspring, at the opposite or speedometer end of the rod 23 and in themanner suggested by the disclosure in Figure 4. In this `case therodvwould no longer be a push Aand pull but a pull andpull rod. With srings at opposite ends the rod j would only ave to' be guided atdifferent points to change its direction as desired and would notrequire the flexible nafter more fully described. n

The bushing 16 is adopted to be adjusted relative to thev cam byscrewing the same' .m the yopenin In the drawings and referring particu-15 and when so adjusted is locked in position b .means of a'nut' 25. Theouter end of the orethrough the bush ing is'enlarged to receivethe'downwardly projecting hub portion' 26 of an adjusting nut 27 screwedinto the same. A washer" 28 is positioned between-the nut and bushing toprovide a. tight connection and to pre-l vent any possible leakagelthrough the bush.

ing.

of the flexible guide or covering 24-which encircles the exteriorportion ofthe flexible rod23.' The flexible guide is simply a coiled-bushing 29 through which extends the op# posite end of the rod 23. y

In the showing in Figure -11 the bushing v 29 'is screwed into 'amechanism containing casing 30, hereinafter called'an adopter due` tothe fact that it provides a drivlng'connectlon which can be adopted todifferent driving shafts, such for instance, as thev shaft 31 of aconventionalformof instrument 32, suchas the shaft driven speedometerpartially shown in Figure 1. The con-` The nut 27 has connected theretoone end u I guide 24-liere iet nection with the shaft 31 is made bymeans of a tang 33 journalled in the end .of the casing 30 opposite theend into which the bushing 29 is screwed. The tang 33 constitutes apinion shaft and is provided on its inner end with a bevel pinion34'which meshes with a bevel gear 35 carried by a stub shaft 36journalled in the housing 30, as shown in Fig. 3,. The gear 35 is drivenin a clockwise direction from the rod v 23 which leads into the casing30 through a iiat V-slot 37 -Which slot acts to maintain the rod in aplane parallel to the face of the gear 35. The rod is connectedeccentrically to the gear 35 by means of a crank 38 pivotally connectedto a pin 39 extending from the gear 35 as shown more particularly inFigure 3. Flat leaf springs 404l and 41 are disposed on opposite sidesof the axis of the gear 35; are fastened at one end to the casing 30 andhave their free ends disposed in the path of movement of the pin 39. Bythis construction it will be appreciated that the gear 35 ,will not onlybe carried over a dead center but will always rotate in the samedirection.

rThis form of mechanism for converting neeiprocatory into rotary motionhas been selected `for illustration because it gives uniform. rotarymovement which is necessaryY in driving speedometers of the magnetic orblast type. ln the case of speedometers of the centrifugal vgovernortype the same necessity for exact uniform rotary movement does notexist. y

lt is to be understood therefore that the means illustrated fortranslating the reciprocatory movement of the rod 23 into the rotarymovement of the speedometer drive shaft is merely suggestive of oneapproved means for eiiecting this translation and any well known form ofdirection translating mechanism may be substituted for the formillustrated.

lt is within the scope of this disclosure to vary the gear ratio ofpinion 34 and gear l35 so as to drive the speedometer at diiferentspeeds and in order to permit ready access to the casing 30 it isopened. at one side, as shown in Figure 3, which opening is designed to.be covered by a lubricantftight closure 301.

ln the modified showing in Figure 4 the reciprocating power transmittingrod 23 is connected directly lto an instrument actuating member in theform of a plunger 42 which is mounted for reciprocatory movement in aguiding member 43 forming part of the' instrument casing. This guidingmember provides a housing for a spring 43 which bears at one end againstthe plunger 42 and at the other end against the bushing The spring actsto project 'the plunger 42 upwardlyin the showing in Fig. so as tc pullon the rod 22S-as previously suggested. Here again the spring acts in amanner similar'to the .guide 24 to maintain the rod in substantiallyv astraight line.

While reference has been made herein speciiically to a speedometer driveit is obviously within the'scope of the invention to` drive odometersand other forms of instruments for indicating Vsome function of rotationof the propeller shaft. While a twothrow form of cam 14 is disclosed inFigure 2 it is appreciated that the number of throws of the cam will bevaried dependent upon the rate of reciprocation' at -which it is desiredto drive the rod 23. Preferably the face of the cam should be designedto give a uniform constant motion tothe gear 35.

As both the rod 23 and its guide 24 may .connection would increase atthe same rate and the extent of reciprocation would not be effected.Hence, heat expansion will have no effect on thepush and pull rod.

It is the usual practice at present to supply the supplemental casing 13with the lubricant from the main casing l0 and in this way the cam 14 isat all times embedded in lubricant. With the present disclosure mountedin place the plunger 17. and the part of the rod 22 will likewise bedisposed in the lubricant. As the rod reciprocates it will slowly carrythe lubricant out of the casing with a step-by-step motion and shift thelubricant' along the rod into the space between the rod and its guide;through' the casing 30 and eventually into the-speedometer itself. I

lt is further suggested that the 'guidebe inclosed within an oil-proofflexible covering 44, preferably a water-proof woven fabric. Thedisclosure thus constitutes a selflubricating drive and with the partsthus 'lubricated the possibility of stripping gears and excessive wearis eliminated.y

llVhile l have shown and described and have pointed out in the annexedclaims, certain novel features of my invention, it will be understoodthat various omissions, substitutions and' changes in the form anddetails of the device illustrated and in its operation v may be made bythose skilled in the art without departing from the spirit of theinven'tion.

l movement of therod.

cluding a cam fixed to the transmission i shaft, a cam plun er engagingthe cam and reciprocated there y, a guided flexible rod attached at oneend to and reciproeated 'by the plunger and means at the opposite'end ofthe fiexible rod for translating the reciprocatory `movement of the rodinto rotary movement of the speedometer'shaft.' f

2. 'A speedometer. drive including a bush-l ing provided with means formounting the sainejin a transmission easing, a cam eont-rolled plungermountedin the bushingV for reciprocatory movement and adapted to beactuated by a shaft in the transmission 'c'as-A ing, a sprin housed inthe bushing and bearing on the p unger, a second bushing, a fiexibleguide secured atopposite ends to said ing a function of themovement'ofsaid shaft and connecting means at the'other end* of the rodfor causing its reeiprocatoryl bushings, a power transmitting rodextending through the flexible guide into the bush- .b

ings and secured at one end to the plunger to be .reciprocated therebyand means at the other end for loperatively connecting the-reciprocatingrodto a speedometer to actuate the same.

3. In a device of the class described, the f con'ibinati'on with acasing having power shaft mounted therein for rotary movement.

anda cam fixed to the part of the shaft vwithin the casing,- a bushingfittedto'inytri'ide into said easing, a spring controlled camplungerguided .for reciprocatory movement in said bushing and disposedin. oper-'- ative engagement with said cam to Vbe reciprocated therebylin its rotary movement,. a rod mounted for reciprocatory movement;v

and. attached at one end to said plunger to be actuated thereby, aninstrument posrtioned'exteriorly of thevcasing forfindicatmovement toactu-ate said instrument.

` 4. In an automotive vehicle, the combination -of a casing,v atransmission shaft journalled in the casing, an instrument` for 'lindicating a 'function' of the movement of the shaft, said casing andinstrument ca-v pable of relative bodily movement, a flexi ble drivingconnection between 'the shaft and said instrument permitting said relative movement between the casing vandinstrument, said connectionincluding a flexible rod' havingv a freedom of movement both lonitudinally and transversely, and means witIi-in the casii'ig for.preventing rotary 5. In a power' transmission, the combination with adriving inember'and a driven member both mounted for rotary movement andadapted forrelative bodily movement',

'of a flexible driving connection therebetween, said'connectionincluding a exible reeiprocatingrod, n'ieans at one end of. theconnection :tor translating the rotary movement of the driving memberinto reciproca- `ate an instrument. f

9. In. an instrument. drive, 'the combination. of a single, flexiblepower transmitting member' mounted for reciprocatory move' A'ment aiiexibl'e'- guide forthemember ex- -tending lengthwise thereof, means atone 4end of' the member for moving the saine in .tory movement of therod and means at the other endof the connection for translating thereeiprocatory movement` or' the rod into the rotary movement ofthe-driven member and means for guiding said rod in all posi tions ofthe same. V

6. In a power transmission, the combination Awith a driving memberv anda driven member both mounted for rotary movement, of a flexibledriving.- connection therebetween, said connection Aincluding a flexiblereciprocating rod, means at one end. of the connection fortranslatingthe rotary movement of the .driving member into reciprocatory movementof the rod and means at the other end of the connection for translatingthe reciprocatory movement of the rod -into the rotary movementof thedrivenmemtion with a rotary `driving member and a driven member, of aflexible driving connection therebetween, sai-d connection including a4power transmitting member, -oapable of recip-rocatory -movement in thedi rection of i its length, a fiexible tubular member enclosing a partofthe flexible power transmitting member for guiding the same in' itsreeiprocatoryl movement and` means jat one end of the connection for.translating the rotary movement of the `driving member 'into' thereciprocatory vn iovement of 'ting member.

the flexible powertransmit-l 8.i-In an instrument drive', thecombination of a. exible rod constituting a power ytransmittingv member,a flexible guide. en-

7. In a power transmission, the'combina-4 closing a part of therod,fmeans at one end ofthe rod` for reciprocating the same andmea-iisat theopposite end for lcausing the reciproeatory movement of therod act-u- `the rod and acting to prevent the same from kinking.

11. A speedometer drive constituting a connection between thetransmission of an ics' iis

automotive vehicle and a speedometer, said drive including a plunger andmeans for actuating the same from a transmission shaft, a mounting forthe plunger adapted to be installed in the transmission casing, al

flexible reciprocating rod actuated by the plunger and an adaptor forconnecting the reciprocating rod in operative relation to a; speedometerto drlve the same, said connection constituting a complete unitadaptedfor connecting the transmission shaft with dif-4 a stepbystep movementto the instrument.

13. In a self-lubricating speedometer drive, the combination of aflexible power' transmitting rod, a v,casing for the same,

v means at one end for connecting the same to a speedometer, means atthe other end for lubricating the rod, said rod in its reciprofsame andguided therein for reciprocatory' movement, a gear, a crank connectionbetween the crank and the gear, means for' causing the gear to turn inone direction and means for connecting the gear 4to a speedometer todrive the same.

16. In a speedometer drive, the combina-` tion of a casing, mechanismhoused thereinV for translating one form of motion into Vanother form,power transmitting means mounted in the casing for reciprocatory motionand operatively connected to said mechanism and means controlled by thereciprocation of saidv means for driving'a speedometer. 17. In aspeedometer drive, the combination of a reciprocating' iex'ible powertransvmitting rod, a flexible guide for the same,

a spring acting on the rod and tending to move the same in one directionand a speedometer actuatingA coupling vmeans for connecting the' rodwith a speedometer., l

18. In a speedometer drive, the combination of a casing, a plug intrudedthrough the side of the casing and constituting a piston cylinder, aplunger'slidablyv mounted therein, means for preventingrotation of theplunger in the casing, a lieXible rod extending axially through thecylinder and disposed in spaced relation to the wallv of the cylinderand proj ectin casing, a coiled spring gui the lflexible rod within thecasing, 'bearing on the plunger to move the same in one di- -rection,said spring being in spaced relationto the wall ofthe cylinder andacting on the flexible-rod to prevent the same from kinking or bendinginto Contact with the cylinder wall;

19. In a device. of the class described, the combination of a 'powertransmitting rod mounted for reciprocatory movement and adapted to feeda lubricant along the same wit av step-by-step movement,- a fiexibleguide for the same, and a lubricant-proof exible covering vfor the uide.

20. In a device of the c ass described, the combination of a powertransmitting -rod mounted' for reciprocato'ry movement andl adapted tofeed a Vlubricant along the same. with a step-by-step movement, and alubricant-proof flexible covering for the rod.

Signed at New York city, in the county of New York and State of NewYork, this 12th day of April A. D. 1922.

HOWARD J. MURRAY.

exteriorly of the ed onthepartof

